链表的增删改查的操作

     看来几篇博客，自己还没有实践

#include <stdio.h>#include <malloc.h>#define LEN sizeof(struct student)/*----------------数据定义----------------------*/ //定义一个学生信息的结构体,包括学号,姓名和结构体类型的指针 struct student{    long num;                //学号     char name[128];            //姓名     struct student *next;    //结构体指针 };typedef struct student * stuNode;int n=0;                    //全局变量,记录链表的长度  /*---------------函数声明---------------------*/ stuNode Create();            //创建一个新的链表                     void Print(stuNode head);    //通过传入的链表头指针打印整个链表 stuNode Delete(stuNode head,int num);    //通过传入的链表头指针和学生学号删除节点 stuNode Insert(stuNode head,stuNode newStu);    //依照学生学号的顺序向链表中插入新元素 /*---------------函数定义----------------------*/struct student *Create(){    struct student *head,*p1,*p2;        //开辟一个LEN大小的空间,并让p1,p2指针指向它     p2=p1=(struct student *)malloc(LEN);    //将头指针置为NULL     head=NULL;        //创建链表节点并给节点的元素赋值     printf("请输入学生的学号和姓名:");    scanf("%ld %s",&p1->num,p1->name);    while(p1->num!=0)    {        n=n+1;        if(NULL==head)        {            head=p1;        }        else        {            p2->next=p1;        }        p2=p1;        p1=(struct student *)malloc(LEN);        printf("请输入学生的学号和姓名:");        scanf("%ld %s",&p1->num,p1->name);    }    //将尾节点的指针置为NULL     p2->next=NULL;    return head;}void Print(struct student *head){    struct student * p;    p=head;        //判断链表是否为空     if(NULL==head)    {        printf("链表为空!\n");        return head;    }    else    {        //循环打印链表中的元素         printf("%d 个记录分别为:\n",n);        while(p!=NULL)        {            printf("%ld %s\n",p->num,p->name);            //指针指向下一个节点             p=p->next;        }    }}struct student *Delete(struct student * head,int num){    struct student *p1;    struct student *p2;    p1=head;    //判断链表是否为空     if(NULL==head)    {        printf("链表为空!\n");        return head;    }    //遍历节点,判断当前节点是不是需要删除的节点及是否为尾节点    //如果找到相应节点,或者已经遍历到尾节点就跳出循环     while(p1->num!=num&&p1->next!=NULL)    {        p2=p1;        p1=p1->next;    }    //判断是否找到相应节点     if(p1->num==num)    {        //要删除的节点是不是链表的第一个节点        //如果是,就将头指针指向该节点的后一个节点        //如果不是,就将该节点的前一个节点的指针指向该节点的后一个节点         if(head==p1)        {            head=p1->next;        }        else        {            p2->next=p1->next;        }        n=n-1;        printf("%ld 节点已删除.\n",num);    }    else    {        printf("链表中没有要删除的元素.\n");    }    return head;}struct student *Insert(struct student * head,struct student * newStu){    struct student *p0;    struct student *p1;    struct student *p2;    p0=newStu;    p1=head;    //判断链表是否为空,如果是空链表,就将新节点作为第一个节点     if(NULL==head)    {        head=p0;        p0->next=NULL;    }    else    {        //遍历每一个节点中的学号,与新学号比较大小        //如果找到一个学号比新学号大,就将新学号的节点插入它之前         //如果尾节点的学号仍比新学号小,就将新节点插入到链表尾部         while((p0->num > p1->num)&&(p1->next!=NULL))        {            p2=p1;            p1=p1->next;        }        //找到一个比新学号大的节点         if(p0->num <= p1->num)        {            //判断该节点是否为头节点,如果是,则将新节点设置为头节点             if(p1==head)            {                head=p0;            }            else            {                p2->next=p0;            }              p0->next=p1;        }        else        {            p1->next=p0;            p0->next=NULL;        }    }    //链表长度加1     n=n+1;    printf("%ld 插入成功!\n",newStu->num);    return head;}void main(){    struct student *head;    struct student *stu;    int num;    head=Create();    Print(head);    printf("请输入要删除的学号:");    scanf("%ld",&num);    while(num!=0)    {        head=Delete(head,num);        Print(head);        printf("请输入要删除的学号:");        scanf("%ld",&num);    }    printf("请输入要插入的节点:");    stu=(struct student *)malloc(LEN);    scanf("%ld %s",&stu->num,stu->name);    while(stu->num!=0)    {        head=Insert(head,stu);        printf("请输入要插入的节点:");        stu=(struct student *)malloc(LEN);        scanf("%ld %s",&stu->num,stu->name);    }    Print(head);}

　参考：

#include<stdio.h>#include<stdlib.h>#define LEN sizeof(struct student)struct student{    int num;    double score;    struct student *next;}; //创建一个链表struct student * create(void){    struct student *p1,*p2,*head;    int n = 0;    p1 = p2 = (struct student *)malloc(LEN);    scanf("%d%lf",&(p1->num),&(p1->score));    while(p1->num!=0){        n++;        if(n==1){            head = p1;        }else{            p2 = p1;        }        p1 = (struct student *)malloc(LEN);        scanf("%d%lf",&(p1->num),&(p1->score));        p2->next = p1;    }         p2->next = NULL;    return head;}struct student *delw(struct student *start,int num){    struct student *p1,*p2;    //链表为空    if(start==NULL){        printf("\nlist null!\n");        return NULL;    }    p1 = start;    p2 = NULL;    //链表不为空    //链表只有一个元素，且即为所要找的元素    /*if(p1->next==NULL&&p1->num == num){        printf("there is only one element and that is it!");        return NULL;    }*/    while(p1->next!=NULL&&p1->num!=num){        p2 = p1;        p1 = p1->next;    }         if(num == p1->num){        if(p1 == start){            return start->next;        }else{            p2->next = p1->next;        }    }else{        printf("number not found!");    }         return start;} struct student *del(struct student *head,long num){     struct student *p1, *p2;    //链表为空    if(head == NULL){        printf("\nlist null!\n");        return head;    }    //链表不为空    p1 = head;    while(p1->next!=NULL&&num!=p1->num){        p2 = p1;        p1 = p1->next;    }    if(num == p1->num){        if(p1 == head){            head = p1->next;        }else{            p2->next = p1->next;            printf("delete:%ld\n",num);        }    }else            printf("%ld not been found!\n",num);    return head; }//删除一个节点struct student * deleteNode(struct student *start,int num){    struct student *p1, *p2,*before,*after;    //空表    if(start==NULL){        printf("the linktable is null");        return NULL;    }    p1 = p2 = start;    //只有一个节点    if(start->next==NULL){        if(start->num==num){            return NULL;        }    }    //链表不为空(两个以上的节点)    //1:链表的第一个即为所要找的    if((start->num == num)&&(start->next!=NULL)){        return start->next;    }    while(p1!=NULL){        if(p1->num==num){            before = p2;            after = p1->next;        }        p2 = p1;        p1 = p1->next;    }    before->next = after;    return start;} struct student * insert(struct student *head,struct student *stu){    struct student *p1,*p2, *p0;    p1 = head;    p0 = stu;         //链表为空    if(head == NULL){        head = p0;        p0->next = NULL;        printf("the link is null\n");        return NULL;        //链表不为空，比较num，（如22， 33， 55），44应插入至33后面    }else{        //一个元素        //printf("head.next is not null");        //两个以上元素: 22 55 88        while(p1->num<p0->num&&p1->next!=NULL){            p2 = p1;            p1 = p1->next;        }         if(p1->num>p0->num){//            if(p1==head){//p0排到最前                head = p0;                p0->next = p1;            }else{                //p0排到中间                p2->next = p0;                p0->next = p1;            }        }else{//p0排到最后            p1->next = p0;            p0->next = NULL;        }         return head;    }      } void printLink(struct student *p){    struct student *p_afterDeal = p;    p_afterDeal = p;    while(p_afterDeal!=NULL){        printf("num = %d, score = %lf\n",p_afterDeal->num,p_afterDeal->score);        p_afterDeal = p_afterDeal->next;      }}int main(void){         struct student * p_std, * p_afterDel,*p,*p_afterInsert;     struct student newstd = {44,44.4,NULL};    //创建一个链表    printf("创建一个链表：\n");    p_std = create();    printf("创建的链表如下：\n");    printLink(p_std);    //插入一个节点    printf("插入一个节点：44\n");    p = &newstd;    p_afterInsert = insert(p_std,p);    printf("插入一个节点后的列表如下：\n");    printLink(p_afterInsert);    //删除一个节点    printf("删除一个节点：44\n");    p_afterDel = deleteNode(p_afterInsert,44);    printf("删除一个节点后的列表如下：\n");    printLink(p_afterDel);    system("pause");}

/** *C语言实现，用了三个指针操作，没用构造函数 */#include<iostream> using namespace std;struct student {    int data;    struct student* next;};int main(){    int data;    struct student *head,*tail,*temp;    head = NULL;    while(cin>>data && data!=-1) {        temp = (struct student*)malloc(sizeof(struct student));        temp->data = data;        temp->next = NULL;        if(head==NULL) {        head = temp;            tail = head;        } else {             tail->next = temp;            tail = temp;                }             }           tail = head;    while(tail!=NULL) {        cout<<tail->data<<endl;        tail = tail->next;    }    system("pause");    return 0;}/** *C/C++实现，用了三个指针操作，用了构造函数 */#include<iostream> using namespace std;struct student {    int data;    struct student* next;    student(int a) {        this->data = a;        this->next = NULL;     }};int main(){    int data;    struct student *head,*tail,*temp;    head = NULL;    while(cin>>data && data!=-1) {               if(head==NULL) {            head = new student(data);            tail = head;         } else {             temp = new student(data);             //temp用来接收新节点，这样tail的next不会丢失              tail->next = temp;             tail = temp;                       }             }               tail = head;    while(tail!=NULL) {        cout<<tail->data<<endl;        tail = tail->next;    }    system("pause");    return 0;}/** *C/C++实现，用了两个指针操作，用了构造函数 */#include<iostream> using namespace std;struct student {    int data;    struct student* next;    student(int a) {        this->data = a;        this->next = NULL;     }    student(int a, struct student* p) {        p->next = this;        this->data = a;        this->next = NULL;    }};int main(){    int data;    struct student *head,*tail;    head = NULL;    while(cin>>data && data!=-1) {                   if(head==NULL) {            head = new student(data);            tail = head;                      } else {              tail = new student(data, tail);         }            }           tail = head;    while(tail != NULL) {        cout<<tail->data<<endl;        tail = tail->next;    }    system("pause");    return 0;}

 

参考：http://www.cnblogs.com/yanghuahui/archive/2012/04/15/2451076.html

http://www.cnblogs.com/ligang305/archive/2012/08/25/2656343.html

http://www.cnblogs.com/wolfred7464/p/4335298.html

http://www.cnblogs.com/xnwyd/archive/2010/04/28/1723151.html